title: Soret effect and photochemical reaction in liquids with laser-induced local heating.
abstract: We report a theoretical model and experimental results for laser-induced local heating in liquids, and propose a method to detect and quantify the contributions of photochemical and Soret effects in several different situations. The time-dependent thermal and mass diffusion equations in the presence and absence of laser excitation are solved. The two effects can produce similar transients for the laser-on refractive index gradient, but very different laser-off behavior. The Soret effect, also called thermal diffusion, and photochemical reaction contributions in photochemically reacting aqueous Cr(VI)-diphenylcarbazide, Eosin Y, and Eosin Y-doped micellar solutions, are decoupled in this work. The extensive use of lasers in various optical techniques suggests that the results may have significance extending from physical-chemical to biological applications.
authors.affiliation: Departamento de Física, Universidade Estadual de Maringá, Maringá-PR, Brazil. lcmala@dfi.uem.br
authors.forename: L C
authors.initials: LC
authors.lastname: Malacarne
authors.forename: N G C
authors.initials: NG
authors.lastname: Astrath
authors.forename: A N
authors.initials: AN
authors.lastname: Medina
authors.forename: L S
authors.initials: LS
authors.lastname: Herculano
authors.forename: M L
authors.initials: ML
authors.lastname: Baesso
authors.forename: P R B
authors.initials: PR
authors.lastname: Pedreira
authors.forename: J
authors.initials: J
authors.lastname: Shen
authors.forename: Q
authors.initials: Q
authors.lastname: Wen
authors.forename: K H
authors.initials: KH
authors.lastname: Michaelian
authors.forename: C
authors.initials: C
authors.lastname: Fairbridge
mesh_terms: D003198:Computer Simulation; D006361:Heating / Q000379:methods*; D007834:Lasers; D008956:Models, Chemical; D010777:Photochemistry / Q000379:methods*; D012996:Solutions / Q000737:chemistry* / Q000528:radiation effects*
chemical_list: D012996:Solutions